envsetup: export ANDROID_BUILD_TOP earlier

Change-Id: Ia3497f61f4e9aaeeb793cecd3b4f488f0a48181a
build: edify: fix multiple device assert

Credit to cm
Remove HomeSample from builds

As good as it looks, we already have a launcher (Launcher3)

Change-Id: I87cac70eec30fd62d6f7ecb7777caa9d240fe0ee